1. Field of the Invention
This invention relates to a poly-.alpha.-olefin of novel stereostructure.
2. Description of the Prior Art
It has been well known to date that poly-.alpha.-olefins have isotactic or atactic structure as their stereoforms. With regard to those having syndiotactic structure, however, syndiotactic polypropylene and syndiotactic polystyrene of relatively low tacticities (Japanese Patent Laid-Open No. 187708/'87 and others), hydrogenated products of these syndiotactic polymers (Japanese Patent Laid-Open No. 131263/'89), and the like have only been disclosed. On the other hand, J. A. Ewen et al. have discovered a process for producing a polypropylene by the use of a catalyst comprising a transition metal compound having an asymmetric ligand and an aluminoxane, the process being featured by the high activity per unit amount of the transition metal and the high syndiotacticity of the resulting polymer (J. Am. Chem. Soc., 1988, 110, 6255-6256).
There have not been known up to date .alpha.-olefin polymers of 4 carbon atoms or more which are not of isotactic or atactic structure but have a novel stereoregularity. If these polymers are available, however, it will be expected to use them in a variety of applications based on their stereospecific nature.